Muscular System Flashcards
(105 cards)
1
Q
What are the 3 Types of Muscles?
A
- Skeletal muscle
- Cardiac muscle
- Smooth muscle
2
Q
- It is a long, cylindrical shaped muscles that is attached to bones.
- It is striated and multinucleated.
- Voluntarily controlled.
A
Skeletal muscles
3
Q
Skeletal muscle can be classified based on how it attaches to bones. The two primary types of muscle attachment are what?
A
DIRECT
- In a direct attachment, the muscle fibers are directly attached to the bone, without an intervening tendon.
INDIRECT
- In indirect attachment, the muscle does not directly attach to the bone. Instead, the muscle fibers connect to a tendon or aponeurosis, which then attaches to the bone.
4
Q
- It is branched shape and it is located in the heart.
- Striated and uninucleated. (This is not multinucleated like what the video says)
- The fibers are connected by intercalated discs, which contain gap junctions that allow for the rapid transmission of electrical signals between cells.
- Involuntarily controlled.
A
Cardiac muscles
5
Q
- Muscle fibers are spindle-shaped and located in blood vessels, hollow organs.
- Uninucleated and non-striated.
- Involuntarily controlled.
A
Smooth muscle
6
Q
It refers to the wave-like, rhythmic contractions of the smooth muscles in the walls of hollow organs, particularly in the digestive system. This movement is essential for propelling substances through tubes like the esophagus, intestines, and ureters (the tubes connecting the kidneys to the bladder).
A
Peristalsis or Peristaltic movement
7
Q
What are the functions of the Muscular system?
A
- Movement
- Maintain posture
- Respiration
- Production of body heat
- Communication
- Heart beat
- Contraction of organs and vessels
8
Q
What are the 4 Properties of Muscles?
A
- Contractility
- Excitability
- Extensibility
- Elasticity
9
Q
It is the ability of muscle to shorten forcefully or contract.
A
Contractility
10
Q
The capacity of muscle to respond to a stimulus.
A
Excitability
11
Q
The ability to be stretched beyond its normal resting length and still be able to contract.
A
Extensibility
12
Q
The ability of the muscle to recoil to its original resting length after it has been stretched.
A
Elasticity
13
Q
How many percent of our body is muscles?
A
40%
14
Q
It refer to the connective tissue layers and structures within skeletal muscles.
These layers help organize muscle fibers and provide the structural support needed for contraction and movement.
What are these? Note that there are 4.
A
- Epimysium
- Fascicles
- Perimysium
- Endomysium
15
Q
It is the outermost layer of connective tissue that surrounds the entire muscle or whole muscle.
A
Epimysium
16
Q
A skeletal muscle is subdivided into groups of muscle cells.
These are bundles of muscle fibers (cells) within a muscle.
A
Fascicles
17
Q
It is the layer of connective tissue that surrounds each fascicle within a muscle.
A
Perimysium
18
Q
It is a thin layer of connective tissue that surrounds each individual muscle fiber within a fascicle.
A
Endomysium
19
Q
What is the cell membrane of a muscle fiber (muscle cell)?
A
Sarcolemma
20
Q
The sarcolemma (cell membrane) has many tubelike inward folds, called _________.
A
Transverse tubules or T tubules
21
Q
What are the Three (3) key components of the muscle fiber’s internal structure?
A
- Sarcoplasmic reticulum
- Terminal cisternae
- Muscle triad
22
Q
It is an enlarged portions of the smooth endoplasmic reticulum in muscle cells.
It functions as a storage site for calcium ions (Ca²⁺), which are critical for muscle contraction.
A
Sarcoplasmic reticulum
23
Q
It has a high concentration of calcium, which plays a major role in muscle contraction.
A
Sarcoplasmic reticulum
24
Q
Are the enlarged end regions of the sarcoplasmic reticulum. They are located near the T-tubules and serve as the primary storage locations for calcium ions.
A
Terminal cisternae
25
It is a structural feature consisting of **one T-tubule flanked by two terminal cisternae** of the sarcoplasmic reticulum.
Muscle triad
26
It is the **cytoplasm of a muscle fiber**, which contains many bundles of protein filaments.
Sarcoplasm
27
It is the **bundle of protein filaments.**
**Myofibrils**
Note: Myofibrils consist of the myofilaments, actin, and myosin.
28
Myofibrils is consist of 3. What are these?
* Myofilaments
* Actin
* Myosin
29
It is the basic structural and functional unit of a skeletal muscle because it is the **smallest portion of a skeletal muscle capable of contracting.**
**Sarcomere**
Note: A sarcomere extends from one Z disks to the next Z disk.
30
These are the **lines at each end of a sarcomere** that mark the boundaries between adjacent sarcomeres.
It form a network of protein fibers that both serve as an anchor for actin myofilaments and separate one sarcomere from the next.
Z disks
31
These are alternating regions within a **sarcomere** that create the striated appearance of skeletal and cardiac muscle.
These bands correspond to the arrangement of **thick and thin filaments** within the sarcomere and are key to the muscle’s ability to contract and produce force.
I bands and A bands
32
It is the **lighter region** that extends toward the center of the sarcomere to the ends of the myosin and myofilaments.
It contains only **thin filaments (actin)**, with no overlap of thick filaments (myosin).
I bands
33
This is the **dark staining bands** that extend the length of the myosin myofilaments.
**A bands**
Note: Actin and myosin myofilaments overlap for some distance on both ends of the A band and this **overlap causes the contraction**.
34
These are **thin filaments within the sarcomere** that are essential protein structures within muscle fibers that play a crucial role in the process of **muscle contraction.**
Actin myofilaments
35
Actin myofilaments are made up of **3 components**. What are these?
* Actin
* Troponin
* Tropomyosin
36
It is a molecule that have **binding sites for Calcium and tropomyosin filaments**.
Troponin
37
It resemble bundles of tiny golf clubs.
Myosin filaments or thick myofilaments
38
It have ATP binding sites, ATPase, and attachment spots for actin.
Myosin heads
39
Troponin is a **protein complex** attached to tropomyosin at regular intervals along the actin filament.
It has three subunits. What does this stands for?
* TC
* TT
* TI
* TC - **Troponin Calcium**
* TT - **Troponin Tropomyosin**
* TI - **Troponin Inhibitor**
40
When calcium ions are released into the sarcoplasm during muscle excitation, they **bind to troponin C** (TC), causing the troponin complex to change shape. This shift in troponin **moves tropomyosin away** from the myosin-binding sites on actin, allowing **myosin head** to bind to actin and initiate contraction.
FAMILIARIZE ONLY
41
How does the myosin head move?
Through using ATP (Adenosine Triphosphate)
42
It is the **electrical charge difference** across the cell membrane of an unstimulated cell.
It is due to the inside of the membrane being **negatively charged** in comparison to the outside of the membrane being positively charged.
Resting membrane potential
43
The resting membrane potential exists because of 3 reasons. What are these?
* The concentration of Potassium (K+) is high on the inside and the concentration of Sodium (Na+) is high on the outside. *REMEMBER **PISO***
* There presence of many **negatively charged molecules**, such as proteins, **inside the cell** that are too large to exit the cell.
* The presence of leak protein channels in the membrane that are more permeable to Potassium (K+) that it is to Sodium (Na+).
44
Sodium (Na+) tends to diffuse into the cell and Potassium (K+) tends to diffuse out.
In order to maintain the resting membrane potential, what pump recreates the Sodium and Potassium ion gradient by pumping Na+ out of the cell and K+ into the cell?
Sodium - Potassium pump
45
It occurs when gated cell membrane channels open.
To initiate a muscle contraction, the resting membrane potential must be changed to this potential. What is this?
**Action potential/s**
This happens when a **nerve impulse triggers gated Na+ channels to open** and Na+ diffuses into the cell down its concentration gradient and toward negative charges inside the cell.
46
The increase in positive charge inside the cell membrane is called what?
**Depolarization**
The initial rise in membrane potential as Na⁺ enters the cell, reducing the cell's negativity.
47
It acts as a **trigger point**. It is the critical membrane potential level that must be reached for an action potential to be triggered. Typically, this is is around -55 mV in many neurons.
Threshold
48
It is a rapid change in charge across the cell membrane.
Peaks at around **+30 mV** (depolarization)
Action potential
49
It is the phase in the action potential where the **cell membrane potential returns to its resting negative value** after reaching the peak of depolarization.
It happens when the **opening of gated K+ channels starts**.
**Muscle relaxation**
**Repolarization**
It is due to the exit of K+ from the cell.
50
MUSCLE CONTRACTION process
**Resting Membrane Potential**
* The cell is in a stable, polarized state, usually around -70 mV.
**Threshold**
* A stimulus causes the membrane to depolarize slightly. If this depolarization reaches the threshold level (typically -55 mV), it triggers an action potential.
**Action Potential**
* Once the threshold is reached, an action potential is initiated, starting with depolarization.
**Depolarization**
* The membrane potential rapidly becomes positive as Na⁺ channels open and Na⁺ flows into the cell.
**Repolarization**
* After the peak of depolarization, Na⁺ channels close and K⁺ channels open, allowing K⁺ to exit the cell, bringing the membrane potential back down toward its resting level.
**Return to Resting Membrane Potential**
* After repolarization, the cell membrane stabilizes at the resting membrane potential, ready for the next stimulus.
51
A ______ neuron is a nerve cell stimulates muscle cells.
Motor
52
It is a synapse where the fiber of a nerve connects with a muscle fiber.
Neuromuscular junction
53
It refers to the cell-to-cell junction between a nerve cell and either another nerve cell or an effector cell, such as in a muscle or a gland.
Synapse
54
It is a group of muscle fibers that a motor neurons stimulates.
Motor unit
55
It is the end of a neuron cell axon fiber.
**Presynaptic terminal**
It has electrical output
56
It is the space between the presynaptic terminal and postsynaptic membrane.
**Synaptic cleft**
It has chemical output
57
It is the muscle fiber membrane (sarcolemma).
**Postsynaptic membrane**
It has also electrical conduction
58
It is a vesicle in the presynaptic terminal that stores and releases neurotransmitter chemicals.
Synaptic vesicle
59
These are chemicals that stimulate or inhibit postsynaptic cells.
Neurotransmitters
60
It is the neurotransmitter that stimulates skeletal muscles.
Acetylcholine (ACh)
61
It refers to the **network of nerves** that send signals to and from a particular area or organ in the body.
Nerve supply, or innervation
62
It is a **single contraction of a muscle** fiber in response to a stimulus.
Muscle twitch
63
Is muscle twitch a form of muscle contraction?
Yes
64
A muscle twitch has **3 phases**. What are these?
* Latent phase
* Contraction phase
* Relaxation phase
65
It is the time between the **application of a stimulus** and the beginning of contraction.
[Wala pang contraction but there is action potential]
What phase is this?
**Latent phase or (lag phase)**
Note: This is where the stimulus is applied. There is **no tension yet**
66
It is the time during which the **muscle contracts.**
[May contraction na, nag shorten]
What phase is this?
**Contraction phase**
Note: The tension is increasing.
67
It is the time during which the **muscle relaxes.**
[Tapos na yung contraction and nawawala na yung electrical impulses]
What phase is this?
**Relaxation phase**
Note: Tension is diminishing.
68
There are two mechanisms the body uses to control muscle force and produce smooth, graded movements.
What are the **2 types** of how the muscle works?
Summation and Recruitment
69
In ______, **individual muscles contract** more forcefully.
[Individual (SINGLE) muscles only are moving]
A. Summation
B. Recruitment
**A. Summation**
Example: Lifting a barbell
70
It is the stimulation of **several motor units.**
[The whole body moves]
A. Summation
B. Recruitment
**B. Recruitment**
Example: Running
71
It is a **sustained contraction** that occurs when the frequency of stimulation is so rapid that **no relaxation occurs**.
It is like cramps.
Tetanus
72
**Tetano** (in some languages, particularly Spanish, Filipino, and Portuguese) and **tetanus** refer to the same concept but can have two distinct meanings depending on the context.
**What is difference of tetanus in muscle physiology and in medical context?**
* **Physiological Tetanus:** A sustained muscle contraction in response to rapid stimulation, part of normal muscle function.
* **Infectious Tetanus:** A bacterial infection causing involuntary, severe muscle contractions, often starting with the **jaw (lockjaw)** and spreading to other muscles. It is preventable with vaccination.
73
In cases where a patient is unconscious or unable to actively move, physical therapists (PTs) often use _______, such as **Electrical Muscle Stimulation (EMS) or Neuromuscular Electrical Stimulation (NMES)**.
**machines**
These machines deliver small electrical currents to stimulate muscle contractions, helping maintain muscle tone, strength, and flexibility.
74
What are the **2 Types of Skeletal Muscle Fiber**?
* Slow twitch fibers
* Fast twitch fibers
75
These are specialized for **endurance** and **aerobic activities (use oxygen) like long-distance running**, swimming, or cycling.
The muscles **contract and fatigue slowly.** However, it causes cramps.
Slow twitch fibers
76
It is mostly used by **sprinters**. The muscles contract and fatigue **quickly**.
It uses anaerobic respiration (low oxygen = 150Bpm), which causes our lactic acid to increases and leads to muscle cramps.
Fast twitch fibers
77
The distribution of fibers is **genetically determined.** This is the reason why in sports, "black people" dominates the winning rate. (Subjective tho, not all)
A muscle has a blend of types, with one type dominating.
**Humans have ____ types of fibers.**
A. one
B. both
B. both
78
What is the energy for muscle contractions?
ATP
79
Do we need ATP for the muscles to contract?
Yes
80
What will happen to your muscles if you have no ATP?
81
Muscle fibers are ____ energy-demanding cells whether at rest or during any form of exercise.
A. not
B. very
**B. very**
This energy comes from either aerobic (with O2) or anaerobic (without O2), ATP production
82
It is derived from four processes in skeletal muscle.
ATP
83
Anaerobic production of ATP happens during intensive ____-term work.
A. short
B. long
A. short
84
* Our muscles has stored energy. The conversion of a molecule is called _____.
Creatine phosphate to ATP
85
It is a temporary state of **reduced work capacity.**
Fatigue
86
What causes muscle fatigue?
Overuse of muscle causes tear that leads to fatigue.
* But this is not a bad sign, it just means that your muscle reached its limit and you need to rest.
* **Without fatigue**, muscle fibers would be worked to the point of **structural damage** to them and their supportive tissues.
87
This is **extra energy** or **quick energy**.
**Creatine phosphate**
Taking creatine supplements make the person doesn't feel muscle fatigue. [May disadvantage to]
88
2 causes of Muscle Fatigue
Acidosis and ATP depletion
89
It is **caused by lactic acid**.
Note that Lactic acid happens because of decrease oxygen.
**Acidosis**
You can feel oxidative stress and local inflammatory reactions [After using your muscle, it will hurt for the next 3 days].
90
What are the **two types of muscle contractions**?
* Isometric
* Isotonic
91
What type of contraction has an **increase in muscle tension, but no change in length**?
Examples:
* Patients with casts
* Holding a plank position in a push-up.
* Holding a heavy object steady without moving it.
* Maintaining posture while standing or sitting upright.
Isometric
92
What type of contraction has a **change in muscle length with no change in tension**?
Examples:
* Bending the arms
* Yoga (slow movements)
Isotonic
93
What are the **2 Types of Isotonic**?
* Concentric
* Eccentric
94
It is a **type of Isotonic contractions** in which **muscle tension increases as the muscles shortens.**
Example:
* Lifting a weight during a bicep curl, where the bicep muscle shortens as it contracts.
Concentric
95
It is a **type of Isotonic contraction** in which **tension is maintained** in a muscle, but the opposing resistance causes the **muscle to lengthen.**
Example:
* Lowering a weight during a bicep curl, where the bicep muscle lengthens as it controls the descent.
Eccentric
96
Muscle tone can be ____ and _______.
Flabby and well-toned
97
It is the **constant tension** produced by body muscles over long periods of time.
It is responsible for keeping the back and legs straight, the head in an upright position, and the abdomen from bulging. [MAINTAINING POSTURE]
Muscle Tone
98
When you exercise, you burn ____ calories.
A. more
B. less
A. more
99
What are the **3 Muscles of Mastication**?
* Temporalis
* Masseter
* Pterygoids (two pairs)
100
THORACIC MUSCLES
* Elevate ribs for inspiration
External intercostals
101
THORACIC MUSCLES
* Depress ribs during forced expiration.
* Accessory muscles for breathing.
Internal intercostals
102
THORACIC MUSCLES
* Moves during quiet breathing.
Diaphragm
103
What are the muscles for injection in **infants**?
Include the second muscle option too.
**Vastus Lateralis (thigh area)**
* Second option: **Rectus femoris**
104
What is the muscle for injection in **Adult**?
Deltoid
105
What is the muscle for injection in adults if we are going to inject high volume of substance?
Gluteus medius
